Pump

ABSTRACT

A diaphragm pump having an enclosed sealed pumping compartment and a pair of one-way pumping valve elements providing a valve chamber therebetween. A pumping liquid passageway is provided communicating between the valve chamber and the uppermost portion of the pumping compartment sloping in an upward direction to the valve chamber for gravity retention of liquid in the compartment and the passageway. A flushing liquid passageway is provided communicating into the lower portion of the pumping compartment. The pumping compartment is free of other liquid communication for preventing introduction of air into the pumping compartment and the passageway especially while the pump is stopped.

United States Patent 1191 1 3,802,807 Kilayko Apr. 9, 1974 [54] PUMP FOREIGN PATENTS OR APPLICATIONS 1 lnvemofi q Locsm Kllayko, 1.950.741 5/1970 Germany 417/388 Auburndale, Mass.

[73] Assignee: Precision Control Products im ry a i er-William L. Freeh Corporation, Waltham. Mass.

1221 Filed: June 2, 1972 I571 ABSTRACT [2]] Appl NOS 259,288 diaphragm pump having an enclosed sealed pump- Ing compartment and a pan of one-way pumpmg valve elements providing a valve chamber therebetween. A [52] U.S. Cl. 417/430, 417/435 pumping liquid passageway is provided communicat- [51] Int. Cl. F04b 21/00 ing between the valve chamber and the uppermost Field of Search 17/568, 567, 435; 2/8 portion of the pumping compartment sloping in an upward direction to the valve chamber for gravity reten- [56] References Cited tion of liquid in the compartment and the passageway.

UNlTED STATES PATENTS A flushing liquid passageway is provided communicat- 3,298 319 l/l967 Savage; 417/430 ing into the lower Pomo" of the Pumping 2444:5216 7/1948 Wuench 417/435 The Pumping Compartment is free of other q- 1,313,z45 3/1919 Andrews 4 7 430 uid communication for,preventing introduction of air 3,559,644 2/1971 Stoft 4l7/435 into the pumping compartment and the passageway 1,599,625 9/1926 Whitlock 92/87 especially while the pump is stopped. 1,483,143 2/1924 Whitlock 92/87 3,314,372 4/1967 Sutton 417 435 2 Clams, 2 Drawlng Flglll'es Y I w I 1 T 35 ll 39 l2 V F43 4l PUMP This invention relates to pumps and more particularly to a diaphragm pump of the type having a sealed pumping compartment.

Diaphragm pumps of the type having a sealed pumping compartment are well known, being shown and described, for example in U.S. Pat. No. 2,741,187.

Although such pumps are widely used in the chemical and the like industries for metering purposes by supplying a stream of liquid at a predetermined rate, they have proved to be subject to certain deficiencies. One of these is especially apparent in intermittent use, in which air enters the pumping chamber, so that the pump will not automatically resume pumping, but must be primed. Another is apparent in the pumping of slurries, in which solid particles tend to collect in the pumping compartment, to the extent that it must periodically be cleaned to keep the pump in operation.

Accordingly, it is a major object of the present invention to solve the above and other problems by providing a novel diaphragm pump which will automatically resume pumping in intermittent use.

It is another object of the present invention to provide a novel diaphragm pump especially adaptable for the pumping of slurries.

It is still another object of the invention to provide a novel diaphragm pump of practical and economical construction.

The present invention accomplishes the above objects by providing in a diaphragm pump having an enclosed sealed pumping compartment with an uppermost edge portion, pumping valve means including a pair of one-way'valve elements, such as ball valves, providing a valve chamber therebetween, said one-way valve elements being spaced from one another for flow of liquid through said chamber, preferably in an upward direction, pumping liquid passageway means communicating between said valve chamber and only said uppermost edge portion of said pumping compartment sloping in an upward direction from said uppermost edge portion to said valve chamber, for gravity retention of liquid in said pumping compartment and flushing liquid passageway means communicating into the lower portion of the pumping compartment and valve means therefor, said pumping means being free of other liquid communication for preventing introduction of air into said pumping compartment'and passageway means. Timing means may be provided for said flushing liquid valve means.

For the purpose of more fully explaining the above and still other objects and features of the invention, reference is now made to the following detailed description of a preferred embodimentthereof, together with the accompanying drawings, wherein:

FIG. 1 is an exploded isometric view of the pump of the invention, and

FIG. 2 is a cross sectional elevation thereof.

Referring to the drawings, the diaphragm pump includes a main housing of a cast aluminum alloy or other suitable material having a circular boss 12 on one side wall to which the pump housing is secured. The pump housing comprises a circular, corrosion-resistant base member 14 in the form of a shallow cup secured by stainless steel screws 16 to the boss 12. A reciprocable rod 17 extends slidably through the boss 12 and a hole in the center of the member 14 to vibrate a diaphragm 20 which is mounted on or engaged by the end screw 24 by which the diaphragm is detachably secured to the rod. The margin 28 of the diaphragm extends radially from the rim of the disk 22 and is securely gripped between the annular end face of the base member 14 and the rim of a cylindrical block 30 of transparent or opaque plastic material which, with the member 14, forms the pump housing. This block has a central recess at its inner end forming an enclosed sealed pumping compartment 32 of which the diaphragm 20 is a vibrating wall. The interior diameter of the block 30 at its recessed end is equal to that of the number 14. Screws 40 and 46 of stainless steel or other'suitable corrosion-resistant material pass through the margin of the block 30 and diaphragm margin 28 and into the base member 14 to secure these parts together. The screws 40 and 46, or the holes for them, do not extend through the base member 14. Therefore, it is impossible for any leakage that will follow along the screws 40 and 46 to reach, and corrode, the circular boss 12. The rim of the member 14 is preferably but not necessarily recessed to be fitted by the margin 28 of the diaphragm. The diaphragm forms with the member 14 a chamber 42 from the bottom of which a vent 44 extends to the outside.

The base member 14 is preferably of a thermosetting synthetic resin of the phenol-formaldehyde type which is impervious to corrosive liquids, is to a considerable degree heat resistant, and is an effective heat insulator. Ordinarily, the chamber 42 will be free of the liquid which is being pumped by vibration of the diaphragm, but if any such liquid should get into this chamber either by seepage around the screws 40 or by rupture of the diaphragm it will drain out through the vent 44. The base member 14 thus completely protects the metal housing 10 from corrosive liquid and also protects the transparent or opaque housing member 30 from the heat generated by the electric motor (not shown) enclosed in the main housing 10.

According to the present invention, the above described diaphragm pump is provided with a novel arrangement of valves and a connecting passageway for gravity retention of liquid in pumping compartment 32, even when the pump is stopped, so that priming upon restarting is unnecessary and flushing of said compartment may be accomplished. In addition, the liquid being pumped does not pass through the pumping compartment, so contamination thereby is reduced, as is especially important in the pumping of slurries.

To these ends, there is mounted on the outer face of block 30 a valve housing 50 by means of screws 40, 46 passing through the margins of the block 30 and diaphragm 28 and into the base member 14 to secure these parts together. Valve housing 50 has mounted therein upper and lower one-way valve elements, providing an'upper outlet connection 54 and a lower inlet connection 58, respectively. Said valve elements include upper and lower seat elements 52 and 56, respectively, and upper and lower ball elements 53 and 57, respectively, said upper and lower valve elements being vertically spaced from one another to provide a valve chamber 55 therebetween. As best seen in FIG. 2, a pumping liquid passageway is provided communi' cating between valve chamber 55 and only the uppermost edge portion of pumping compartment 32, said passageway sloping in an upward direction to said valve chamber for gravity retention of liquid therein. Such pumping liquid passageway preferably includes a passage 62 through block 30, lsoping upwardly from the uppermost peripheral edge portion of pumping compartment 32 and communicating with an upwardly sloping passage 64 in valve housing 50 opening into vaive chamber 55. Also provided is a flushing liquid passageway communicating vertically into the lower end of pumping compartment 32. Said flushing liquid passageway includes a vertical passage 31 through block 30 and a right angle passage 33 through connector 35. Connector 35 is attached to block 30 by hollow bolt 37 which also can be removed to provide a vertical drain passageway into the bottom of pumping compartment 32 through passage 31. A flushing valve 41, preferably of the electrically operated type, is connected to connector 35 by a right angle fitting 39. Said valve may desired.

7 In operation, the pump of the invention is mounted in a vertical position, as shown, and, preferably, for upward flow of liquid through the valve chamber 55. With the pumping chamber 32 and theupwardly sloping passageway communicating with valve chamber 55 full of liquid, stopping the pump, even to the extent of introducing air into valve chamber 55, will not result in losing prime, since the pumping compartment does not drain and hence introduction of air into the pumping compartment and connecting passageway is avoided. Furthermore, since the introductory liquid to a large extent remains in the pumping compartment and passageway, with the liquid in the latter simply moving back andforth as shown by the double headed arrow 65 in FIG. 2, to accomplish the pumping action through chamber 55 by operating the pair of ball valves, mixing of the introductory liquid with that passing through the chamber occurs only to a limited extent, if at all. For this reason, clogging of the pumping compartment by entrained solid particles, as when pumping slurries, is much reduced, especially if the liquid with whichthe pumping compartment and passageway is initially filled be'free of solid particles. Should it be desired, however, to flush the pumping compartment by clear liquid,

valve 41 can be opened, either periodically by timer 43 or otherwise to accomplish this by introducing liquid to i the inlet of said valve, as indicated by arrow 45. Drain- I .age of the pumping compartment can be accomplished by removing bolt 37.

Of course, if desired, the pump can readily be disassembled for draining and cleaning by removing its screws 40 and 46. i

What is claimed is:

' be operated periodically by a timer 43, orotherwise as l. A diaphragm pump having an enclosed sealed pumping compartment with an uppermost edge portion pumping valve means including a pair of one-way valve elements providing a valve chamber therebetween' said one-way valve elements being vertically spaced from one another and arranged for upward flow of liquid through said valve chamber pumping liquid passageway means communicating between said valve chamber and only said uppermost edge portion of said pumping compartment, sloping in an upward direction from said upper most edge portion to said valve chamber, for gravity retention of liquid in said pumping compartment and passageway means flushing liquid passageway means communicating into the lower portion of said pumping compartment flushing valve means connected to said flushing liquid passageway means, and timing means operably connected to said flushing valve means, I said pumping means being free of other liquid communication for preventing introduction of air into said pumping compartment and passageway means.

2. A diaphragm pump having a mouable diaphragm and a pump housing defining a pumping compartment with an uppermost edge'portion,

pumping valve means including a pair of one-way valve elements providing a valve chamber therebetween said one-way valve elements being vertically spaced from one another and arranged for upward flow of liquid through said valve chamber pumping liquid passageway means communicating between said valve chamber and only said uppermost edge portion of said pumping compartment sloping in an upward direction from said uppermost edge portion to said valve chamber, for gravity retention of liquid in said pumping compartment and passageway means v flushing liquid passageway means providing communication between the lower portion of said pumping compartment and the exterior of said pump housing, and

flushing valve means located exterior to said pump housing and connected to said flushing liquid passageway means and to an external source of flushing liquid said pumping means being free of other liquid communication for preventing introduction of air into said pumping compartment and passageway means. 

1. A diaphragm pump having an enclosed sealed pumping compartment with an uppermost edge portion pumping valve means including a pair of one-way valve elements providing a valve chamber therebetween said one-way valve elements being vertically spaced from one another and arranged for upward flow of liquid through said valve chamber pumping liquid passageway means communicating between said valve chamber and only said uppermost edge portion of said pumping compartment, sloping in an upward direction from said uppermost edge portion to said valve chamber, for gravity retention of liquid in said pumping compartment and passageway means flushing liquid passageway means communicating into the lower portion of said pumping compartment flushing valve means connected to said flushing liquid passageway means, and timing means operably connected to said flushing valve means, said pumping means being free of other liquid communication for preventing introduction of air into said pumping compartment and passageway meanS.
 2. A diaphragm pump having a movable diaphragm and a pump housing defining a pumping compartment with an uppermost edge portion, pumping valve means including a pair of one-way valve elements providing a valve chamber therebetween said one-way valve elements being vertically spaced from one another and arranged for upward flow of liquid through said valve chamber pumping liquid passageway means communicating between said valve chamber and only said uppermost edge portion of said pumping compartment sloping in an upward direction from said uppermost edge portion to said valve chamber, for gravity retention of liquid in said pumping compartment and passageway means flushing liquid passageway means providing communication between the lower portion of said pumping compartment and the exterior of said pump housing, and flushing valve means located exterior to said pump housing and connected to said flushing liquid passageway means and to an external source of flushing liquid said pumping means being free of other liquid communication for preventing introduction of air into said pumping compartment and passageway means. 